RU2088608C1 - Regenerable rubber mixture - Google Patents

Abstract

FIELD: rubber industry. SUBSTANCE: rubber mixture is mixed in the standard mixer. Mixture has the following components, mas. p. p.: "HK"-base rubber crumb, 100; tetramethylthiuram disulfide, 4; zinc oxide, 5; stearine, 2; vat product of 2,4-toluylenediamine rectification, 15. Mixture is pressed to blocks, thickness is 35 mm, at 160 C for 1 h. Plate properties: rupture resistance is 5-6 MPa at 25 C and 2.5-3.6 MPa at 60 C, relative elongation at 25 and 60 C - 200 and 80-100%, respectively. EFFECT: improved quality and property of mixture. 1 tbl

Description

 The invention relates to the field of regenerated rubber compounds, for example, dispersed products of tire production, for the manufacture of monolithic materials, coatings and other products of industrial and cultural purposes.

 A number of technical solutions are known for the disposal of regenerated rubber products, especially rubber crumbs formed during grinding of waste tire products. To do this, post-vulcanization of rubber crumb is carried out by introducing activators into the vulcanizable mixture. Rubrax, di- / 2-benzthiazolyl / disulfide (altax) [1] 11-cyclohexyl-2-benzthiazolylsulfenamide / santokyur / [2] for the case of sulfuric vulcanization, and thiuramdisulfide [3] for sulfurless vulcanization are proposed as such activators.

 The disadvantages of the known technical solutions are due to the fact that in the case of using a santocure, extremely high sulfur concentrations of 24% with respect to rubber crumb are required / the content of a santocure is 0.74% / [2] and the use of rubrax and altax is effective in combination with the outcome of phthalic production anhydride [1] ie a product of variable composition, the low adaptability of use of which is due to its resinous nature (sticking to the walls, difficulty in mixing, uneven distribution over the volume of the mixture). In addition, both of these solutions relate to the direction of sulfuric post-vulcanization. Therefore, they are analogues of the invention.

Closest to the invention in technical essence is a solution involving the introduction of tetramethyl tiuramdisulfide [3] providing post-vulcanization of crumb rubber in the absence of sulfur. This solution is selected as a prototype. The disadvantage of the prototype is the relatively low cohesive strength of the vulcanizates: the tensile strength is 3.5-4.5 MPa. However, the main limitation is the very low temperature resistance of the vulcanizers: at 60 ^o C, this indicator decreases to 1.0-1.5 MPa. Naturally, these features fundamentally limit the scope of the prototype.

 The essence of the invention lies in the fact that in addition to tetramethyl thiuramdisulfide, zinc oxide and stearin are taken as regeneration activators, and an active modifier of the distillation product of 2,4-toluylene diamine / KRDA / is additionally introduced in the following ratio of components, parts by weight

Dispersed tire waste 100
Tetramethylenethiuram disulfide 4
Zinc Oxide 5
Stearin 2
VAT residue of the distillation of 2,4-toluylenediamine 10 20.

 As a result, the strength of vulcanizers at room and elevated temperatures increases.

In contrast to the prototype, the regenerated rubber mixture contains a zinc oxide-stearin and KRDA system, which is relatively easy to introduce into the system by simple mixing of its components compared to the low-tech resinous waste of phthalic anhydride production. KRDA is characterized by the content of carbon, hydrogen, nitrogen and oxygen 66.6% 6.0% 11.9% 15.5%, respectively. Its main indicators:
Density, g / m ³ 1.25
Melting point, ^o C 150 160
Auto-ignition temperature, ^o C, 513
Flash point, ^o C 294
Explosive limit of suspended dust, g / m ³ 125
MPC in air, mg / m ³ 2
These differences determine the significant novelty of the subject of the invention in comparison with the analogue [1] (on the basis of the absence of sulfur and waste production of phthalic anhydride) and the prototype [3] on the basis of the content of zinc oxide and stearin, which is additional to tetramethyl thiuram disulfide, as well as the active modifier of distillation distillation product 2 4-toluylene diamine. The proof is the lack in the literature, including the patent, of information on the use of these products in their combination for the manufacture of regenerable rubber compounds.

 The possibility of carrying out the invention is confirmed by the following example.

 Example. In a standard mixer, the rubber composition of the composition is mixed, parts by weight

Rubber crumb based on NK 100
Tetramethyl thiuramdisulfide (thiuram D, MD) 4
Zinc Oxide 5
Stearin 2
VAT distillation product 2,4-toluenediamine 15
The prepared mixture is pressed into blocks with a thickness of 35 mm for 60 minutes at a temperature of 160 ^o C. The results of measuring the physical and mechanical properties of products according to standard methods are shown in the table simultaneously with the characteristics of the prototype.

 Thus, the above data indicate that, according to all necessary features, the proposed technical solution meets the requirements for inventions.

Claims (1)

 A regenerated rubber mixture, including dispersed waste from tire production and tetramethylthiuramcisulfide regeneration activator, characterized in that it contains zinc oxide and stearin and an additional active modifier, distillation product of 2,4-toluenediamine rectification at the following components content, parts by weight Dispersed tire waste 100
Tetramethylthiuram disulfide 4
Zinc Oxide 5
Stearin 2
Distillation product of rectification 2,4-toluenediamine 10-20n

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